Article ID: 000078501 Content Type: Troubleshooting Last Reviewed: 04/06/2023

Do differential SSTL and HSTL inputs in Cyclone® III and Cyclone® IV device series require a VREF input to reference?

Environment

BUILT IN - ARTICLE INTRO SECOND COMPONENT
Description

Yes, usage of these I/O standards as inputs does also require a VREF input. This is because in Cyclone® III and Cyclone® IV device series, these differential inputs are treated as two single-ended HSTL and SSTL inputs and only one of them is decoded. Hence a VREF is required to define the signal state.

Resolution

N/A

Related Products

This article applies to 4 products

Cyclone® IV GX FPGA
Cyclone® IV E FPGA
Cyclone® III LS FPGA
Cyclone® III FPGAs